This invention relates generally to the refurbishing of worn turbine components, and, more particularly to a portable grinder assembly for grinding replacement stator vanes to a particular angle.
A major component of turbine engines are the radially extending circularly arranged stator vanes. These circularly arranged stator vanes are supported at their outer ends by an air seal ring and at their inner ends by a suitable hub. Unfortunately, after a period of operation, the vanes utilized in turbine engines such as, for example, the TF-39 engine, tend to become worn, especially in the vicinity of the trailing edge of the airfoil surface.
In the past, the replacement vanes were sized to the appropriate dimensions by either filing by hand or the utilization of milling machines or belt sanders. As is quite evident, utilizing such techniques when replacing a large number of stator vanes (480 per engine) the above approaches prove to be extremely time consuming, tedious and in many instances unreliable. For example, the milling machine approach tends to grab the stator vane and destroy it. The use of the belt sander is even more disappointing since the required accuracy is difficult to achieve and belts must be constantly changed.
Another method of restoring worn turbine components is set forth in U.S. Pat. No. 4,128,929 issued on Dec. 12, 1978. In the above-mentioned patent a complex series of fixtures are utilized in order to successfully restore the worn turbine components. Such a procedure also leaves much to be desired, especially when the replacement of worn stator vanes are being performed in the field.
It is therefore clearly evident from the above description of prior attempts at stator vane refurbishment, that a great need exists for a grinding device for utilization in stator vane replacement which is capable of being operational in the field, reliable, economical to produce and efficient in operation.